Geochemical exploration



Patented Apr. 30, 1940 v UNITED STATES PATENT orrlca GEOCHEMICALEXPLORATION Leo Horvitz, Houston, Tex minor to Esme E. Rosaire, Houston,Tex.

No Drawing. Application June 24, 1937, Serial No. 150,108

2 Claims. (Cl. 23-230) This invention relates to prospecting by 9. beenfound that hydrogen is frequently encounstudy of the emnnations, ormodified cmanations tered and is of significance, and since hydrogenwhich are found in the earth adjacent to buried burns without formingcarbon dioxide, the methdeposits of oil and gas. In particular, this inddescribed above will not show the presence of 5 vention relates to anexploration method which hydrogen. 5 is based upon the amount of waterresulting In the present invention the disadvantages of from thecombustion of gases drawn or forced previously known methods areobviated by anafrom the soil in geochemical prospecting. lyzing theproducts of combustion for water vapor An object of the invention is toprovide a methformed during combustion of a previously del0 od ofchemical analysis of gas samples for the hydrated sample. The first stepof the process of purpose of detection of minute hydrocarbon contheinvention is therefore the removal of all water tents. vapor from thegaseous sample that is to be sub- Another object is. in the method ofgeo- Jected to analysis. This step may be carried out chemicalexploration and research. to improve by any of several well knownmethods. The the laboratory processes so that the sensitivity water freesample is then burned, as by contact 15 to the presence of hydrocarbonsis increased sevwith a hot platinum wire, or filament, the proderaltimes over previously practiced art, a valunets of combustion beingthereafter analyzed able contribution when seeking smallconcenquantitatively for water vapor formed during trations of suchsubstances. combustion. This quantitative determination of A morespecific object is to analyze gases for water vapor formed may likewisebe made by 20 hydrocarbon and hydrogen content by the methany of severalmethods known in the art. 0d of combustion and measure the amount of Theadvantages of the invention become eviproducts of combustion,particularly water. dent from a study of the chemistry involved. InStill another object is to provide a rapid and the following table, thefirst column gives the economical laboratory technique, suitable for useequations involved in the combustion of hydrogen, 25 in the art 01geochemical prospecting wherein a methane, ethane and propane. Otherconstitusingie indication serves satisfactorily to reveal the ents couldbe included but these given are sufilpresence or absence of thecomponents sought. cient to illustrate the invention.

There are references, particularly in the Rus- In the second column isgiven the ratio of sian literature, pertaining to soil gas prospecting.volume of water vapor to the volume of the 30 A reconnaissance method ofprospecting has also particular constituent of the gaseous mixture. beenproposed in which gas is drawn from the In the last column is the ratioof'Qolnme of carsoil', the carbon dioxide normally present there bondioxide vapor to the volume of the subremoved, the gases subjected tothe influence of a stance burned.

glowing wire, and then tested either quaiita- From a comparison ofvolume ratios it is evitively or quantitatively tor the presence ofcardent that the water vapor method is infinitely bon dioxide, which, ifthen present, is assumed more sensitive than the carbon dioxide methodto have resulted from the combustion of hydrofor detecting hydrogen,since hydrogen does not carbons present. form any carbon dioxide oncombustion. For

This method, while useful, has certain disadmethane, the sensitivity istwice as great in this vantages. For instance, if methane is present,method than in the older art. for ethane only one volume of carbondioxide is produced more sensitive, etc. I 50 for each volume of methanepresent; and for While the research leading to this invention, thehigher hydrocarbons, which are present in and the invention itself. isdirected to a prospectmuch smaller quantities, two volumes of carbon ingmethod, it is evident that the generic object dioxide for each volume ofethane originally of the invention might wellberealized in practicepresent, three volumes of carbon dioxide for each of the invention inother environments such as volume of propane present, etc. Further, ithas seeking of leaks around tank farms and pipe lines M and the specialor routine testing for personnel and/or iire hazards in refineries andindustrial plants. In fact. combustible dust, such as carbohydrates(cotton, starch and the like), suspended in air can be evaluatedquantitatively by the method disclosed herein.

There are cases where knowledge of exact chemical composition is neithernecessary nor desirable but where a measure 01 combustible contents of agas is needed. Thus a complete, or ultimate, chemical analysis would besuperfluous. but the proximate analysis herein described will give allthe information needed. It is therefore intended that the description ofthe preferred embodiment is illustrative only, the invention beinglimited only by the appended claims an the prior art.

What is claimed is:

l. The method of prospecting ibr buried hydrocarbon deposits by soil gasanalysis which comprises the steps or collecting samples of soil fromthe earth near the surface, mbjectinz the samples to treatment to evolvethe significant gasesthereimremovingiromthegasesalltraces of water,subjecting the dehydrated gas to combusflon. and analyzing the productsoi combustion for water formed by combustion by the entire tree andcombined hydrogen in the dry gas as an indication of relative proximityof the soil samples to the sought deposits.

2. The method of prospecting for buried hydrocarbon deposits by gasanalysis which comprises the steps of collecting samples of soil fromthe earth, subjecting the samples to treatment 7 to evolve thesignificant gases therein. removing from the gas all traces 0! water,subjecting the dehydrated gas to combustion, and analyzing the productsof combustion for water formed by combustion of the fire and combinedhydrogen in the dry gas.

LEO HORVITZ. 2o

CERTIFICATE OF CORRECTION. Patent No. 2,198,619. April 0, 191m.

LEO nenvirz; v It is hereby certified thet error appears in the printedspecification of. the ahove m'nnbered patent requiring correction asfollows: Page 2,.sec- 0nd column, line 18, claim 2, for the word f'fire"re'ad --free--; and that the laid Letters Patent should be read withthis correction therein that the same may conferm to the recordof thecase in the Patent Office.

Signed and sealed this 9th day of July, A. D. 191w.

Henry Van Aredale, (Seal) Acting Commieeidner of Patents.

